Lennox MLA Series - User Manual

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INSTALLATION/USER

INSTRUCTIONS

2020 Lennox Industries Inc.

Dallas, Texas, USA

THIS MANUAL MUST BE LEFT WITH THE OWNER

FOR FUTURE REFERENCE

WARNING

Improper installation, adjustment, alteration, ser vice or

maintenance can cause property damage, personal

injury or loss of life.

Installation and service must be performed by a li censed

professional HVAC installer (or equivalent) or a service

agency.

General

Refer to the Product Specications bulletin (EHB) for more

product information.

These instructions are intended as a general guide and

do not supersede local or national codes in any way.

Authorities having jurisdiction should be consulted before

installation.

The MFMA Floor Mount Console unit is matched with an

outdoor heat pump unit to create a mini-split system that

uses HFC-410A refrigerant.

Use of Mini-Split System During Construction

Lennox does not recommend the use of its mini-split

systems during any phase of construction. Very low return

air temperatures, harmful vapors and operation of the unit

with clogged or misplaced lters will damage the system.

However, mini-split systems may be used for cooling of

buildings under construction, if the following conditions

are met:

• Air lter must be installed in the system and must be

maintained during construction.

• Air lter must be replaced upon construction comple-

tion.

• The indoor wall unit assembly must be thoroughly

cleaned following nal construction clean-up.

• All mini-split operating conditions must be veried ac-

cording to these installation instructions.

MLA/MPB and

MFMA Series

SINGLE-ZONE MINI-SPLIT SYSTEMS

(208/230V) --

Floor Mount Console

508048-01 7/2020

Table of Contents

General .....................................................................................1

Use of Mini-Split System During Construction..........................1

Included Parts...........................................................................2

Optional Accessories ................................................................2

Indoor / Outdoor Unit Match-Ups..............................................2

Model Number Identication .....................................................3

Typical Single-Zone System Components................................4

System Dimensions ..................................................................5

Outdoor Units .................................................................................... 5

Indoor Units.......................................................................................5

System Clearances ..................................................................6

Outdoor Unit......................................................................................6

Indoor Unit ........................................................................................ 6

Torque Requirements for Caps and Fasteners.........................7

Indoor Unit Installation ..............................................................7

Unit Placement Considerations......................................................... 7

Floor Installation................................................................................ 7

Indoor Unit Condensate Piping Connections .................................... 8

Outdoor Unit Installation ...........................................................8

Placement Considerations ................................................................ 8

Direct Sunlight, Rain, Snow and Ice Protection ................................ 8

Prevailing Winds ...............................................................................9

Buried Refrigerant Pipe Protection ................................................. 10

Outdoor Unit Condensate Piping .................................................... 10

Securing the Outdoor Unit .............................................................. 10

Refrigerant Piping Connections .............................................. 11

Leak Test and Evacuation ......................................................13

Leak Test ........................................................................................ 13

Triple Evacuation Procedure ........................................................... 13

Wiring Connections ................................................................14

Outdoor Unit ...................................................................................14

Indoor Unit ...................................................................................... 14

Unit Start-Up ...........................................................................17

Adding Refrigerant for Longer Line Set ..................................17

Troubleshooting ......................................................................17

Test Run .................................................................................17

Pre-Checks ..................................................................................... 17

Procedure ....................................................................................... 17

Dry Mode Operation (Dehumidication) .................................18

Procedure ....................................................................................... 18

Sequence of Operation ................................................................... 18

User Guide .............................................................................18

Default Settings...............................................................................18

Auto-Restart .................................................................................... 18

Louver Angle Memory Function ...................................................... 18

Refrigerant Leak Detection System ................................................ 18

Manual Operations.......................................................................... 18

Adjusting Airow Direction .............................................................. 19

Adjust the Air Flow Direction Left and Right ................................... 19

How to Clean the Air Filter .............................................................. 19

Error Codes..................................................................................... 19

Optional Programmable Wired Controller...............................20

Programmable ................................................................................ 20

Non-Programmable......................................................................... 20

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Summary

General Installation Overview

Use of Mini-Split System During Construction

Guidance on operating mini-split systems during construction phases to prevent damage.

Included Parts and Accessories

Optional Accessories

List of optional components available for the system.

Indoor; Outdoor Unit Match-Ups

Information on compatible indoor and outdoor unit combinations.

Typical Single-Zone System Components

Torque Requirements for Caps and Fasteners

Indoor Unit Installation

Unit Placement Considerations

Guidelines for selecting the optimal location for the indoor unit, avoiding hazards.

Floor Installation

Instructions for mounting the indoor unit on the floor, ensuring stability and clearances.

Indoor Unit Condensate Piping Connections

Outdoor Unit Installation

Placement Considerations

Factors to consider when positioning the outdoor unit to avoid noise and environmental issues.

Direct Sunlight, Rain, Snow and Ice Protection

Recommendations for protecting the outdoor unit from direct sun, rain, snow, and ice.

Buried Refrigerant Pipe Protection

Securing the Outdoor Unit

Slab or Roof Mounting

Guidelines for securing the outdoor unit onto a slab or roof structure.

Refrigerant Piping Connections

Making Connections (Male to Female Connection)

Step-by-step guide for connecting refrigerant lines using flare fittings.

Flare Nut Torque Recommendations

Specifications for tightening flare nuts to ensure leak-free refrigerant connections.

Leak Test and Evacuation

Leak Test Procedure

Procedure for testing the refrigerant system for leaks using nitrogen.

Triple Evacuation Procedure

Multi-stage process to evacuate the system to the required vacuum level.

Wiring Connections

Outdoor Unit Wiring

Instructions for making electrical connections to the outdoor unit.

Indoor Unit Wiring

Instructions for making electrical connections to the indoor unit.

Single Zone Installation Wiring Requirements

Function of Switches

Auto-Restart Function Setup

How to configure the auto-restart function using DIP switches.

Down Louver Setting

How to set the down louver position using DIP switches.

Adding Refrigerant for Longer Line Set

Troubleshooting

Test Run

Procedure for performing a test run to verify system functionality.

Dry Mode Operation (Dehumidification)

User Guide Features

Default Settings

Describes the system's default settings after a power failure.

Auto-Restart

Explains how the system restarts after a power interruption.

Louver Angle Memory Function

Details the function that remembers the louver position.

Refrigerant Leak Detection System

How the system indicates a refrigerant leak.

Manual Operations

How to operate the unit using the indoor unit's control panel.

Optional Programmable Wired Controller

Programmable Controller Connection

Instructions for connecting the programmable wired controller.

Non-Programmable Controller Compatibility

Information on the incompatibility with a non-programmable wired controller.

This document provides installation and user instructions for Lennox single-zone mini-split systems, specifically the MLA/MPB and MFMA series floor mount console units (208/230V). These systems utilize HFC-410A refrigerant and are designed to provide cooling and heating for single zones.

Function Description

The Lennox mini-split system consists of an outdoor heat pump unit and an indoor floor mount console unit. The outdoor unit contains the refrigerant metering device, compressor, and outdoor coil, while the indoor unit houses the evaporator coil, fan, and control components. The system operates by transferring heat between the indoor and outdoor environments, providing cooling in warm weather and heating in cold weather. Condensate drainage is managed by both indoor and outdoor units. The system is controlled via a wireless remote controller, with an optional programmable wired controller available.

Important Technical Specifications

Voltage: 208/230V, 1-phase, 60Hz.
Refrigerant Type: HFC-410A.
Compressor Oil: PVE oil (Polyvinylether). Mixing with mineral-based or POE oil is not recommended.
Nominal Cooling Capacity: 012 (1 ton) for outdoor units; 012 (1.5 tons) for indoor units.
Line Set Diameters (012 KBtu): Liquid Line: 1/4 in., Gas Line: 1/2 in.
Maximum Line Set Length (012 KBtu): 82 feet (25 meters).
Maximum Elevation (012 KBtu): Outdoor Unit BELOW Indoor Unit: 33 feet (10 meters); Outdoor Unit ABOVE Indoor Unit: 33 feet (10 meters).
Recommended Torque for Flare Nuts: 1/4" (6.35) pipe: 15 ft.-lb. (20 N); 1/2" (9.52") pipe: 41 ft.-lb. (56 N).
Minimum Rear Clearance (Outdoor Unit): 6 inches (152 mm) when mounted on brackets with no obstructions on other three sides.
Minimum Clearances (Indoor Unit): Side View: 4 inches (102 mm) from wall; Front View: 4 inches (102 mm) from wall, 6 inches (152 mm) from floor, 40 inches (1016 mm) service clearance in front.
Wiring: Indoor to Outdoor: 16AWG stranded and unshielded 4-conductor wire. Outdoor to Main Power: 16AWG/9A stranded and unshielded 3-conductor wire.
Condensate Drain Slope (Indoor Unit): Not less than 1/4 inch per foot (18 mm per m).

Usage Features

Control: The system is primarily operated using a wireless remote controller. An optional programmable wired controller (MOSTAT64Q-1) can also be connected.
Operating Modes: Includes COOL, HEAT, and DRY (dehumidification) modes.
Dry Mode (Dehumidification): Operates in cooling mode with a low-speed blower. Temperature setting range is 62°F (17°C) to 86°F (30°C). The blower speed is preset to low and cannot be changed. The unit stops when room temperature is 8°F (4°C) lower than the set temperature due to compensation. Note that indoor units do not have a humidistat and are not recommended as a primary source for dehumidification.
Manual Operations: A display panel on the indoor unit allows for basic operation (AUTO, FORCED COOL, OFF) if the remote control is unavailable.
Auto-Restart: In case of power failure, the system will automatically restart with previous settings if the auto-restart function is enabled.
Louver Angle Memory Function: Some models remember the horizontal louver angle after a power failure. The horizontal louver angle should not be set too small to prevent condensation. Louvers can be set to automatic swing or a fixed position.
Airflow Direction Adjustment:
- Manual Swing: Press the "Air Direction" button on the remote to adjust the louver angle (upward or downward).
- Horizontal Louvers: Manually adjust by holding the knob on the left and right side blades.
Refrigerant Leak Detection System: The LCD screen will display "EC" and the LED indicator light will flash if a refrigerant leak is detected.

Maintenance Features

Air Filter Cleaning: The air filter should be cleaned every two weeks or more frequently in dusty areas to maintain optimum efficiency. Replace the filter if heavily clogged and cannot be cleaned.
Condensate Drain Check: After installation, the condensate drain line must be checked for leaks and proper drainage as part of the commissioning procedure.
Pre-Checks for Test Run: Before performing a test run, ensure electrical safety, refrigerant leak checks, and that liquid and gas valves are fully open.
Troubleshooting: The manual provides a list of error codes with corresponding causes and indicator light flashes to assist in diagnosing issues.
Outdoor Unit Coil Cleaning (Coastal Areas): In coastal areas with salty atmospheres, the outdoor coil should be cleaned with potable water several times per year to prevent corrosive buildup.